US election 2016: Republican and Democratic party conventions in Cleveland and Philadelphia explained

What are the Democratic and Republican National Conventions?

The conventions are the events - held every four years - at which delegates nominate each party’s presidential candidate. They are attended by thousands of delegates and vast numbers of journalists from media outlets across the world. Each party’s conventions is supervised by the Democratic and Republican national committee.

Set-piece speeches from senior party figures are a key feature. But the centre-piece event in each case is the speech by the candidate accepting the party’s presidential nomination, at which the nominee traditionally sets out the tone and terms of the upcoming presidential campaign. Each candidate’s vice-presidential pick, usually chosen before the convention, also addresses the event.

Donald Trump has already announced that Indiana governor Mike Pence will be his vice-presidential nominee. Hilary Clinton has yet to declare her choice of running mate.

In general, both parties’ conventions are essential pieces of political Americana accompanied by a level of razzmatazz largely absent from British party conferences.

Will anything be decided at this year’s conventions?

In terms of candidates, no. Both Hillary Clinton and Donald Trump, have secured enough delegates through primary election victories to be assured of winning the nominations for the Democrats and Republicans respectively.

What will be up for grabs is the content of each party's election platform for November, details of which will be debated on the convention floors and behind the scenes. These set the main principles and aims on controversial issues such as guns, abortion and foreign policy.

Where and when are this year’s conventions?

The Republicans hold their gathering at the Quicken Loans Arena in Cleveland, Ohio from the 18th until the 21st of July.

The Democrats meet the following week from 25th till 28th July at the Wells Fargo Centre in Philadelphia, with some events taking place in the Philadelphia Convention Centre.

What are the differences between the two conventions?

One key distinction is the Democratic party’s use of super-delegates, senior party members and office holders whose affiliation to a candidate is not bound by primary election results.

Mrs Clinton had an overwhelmingly lead over Mr Sanders in super-delegates’ support throughout the primary campaign, a factor which the Vermont senator tried to depict as unreflective of the popular will as he notched up a succession of primary wins.

However, the issue became moot when Mrs Clinton won primaries in California, New Jersey, New Mexico and South Dakota this month, giving her an unassailable lead among “pledged” delegates - those whose vote is dictated by primary results.

Is any drama expected at either parties event?

The Republican convention will almost certainly be accompanied by vocal protests against Mr Trump, but the prospect of a contested or brokered event has receded, despite opposition to his candidacy among party grandees.

Senior figures such as Mitt Romney, the 21012 Republican candidate, and former presidents George Bush Jnr and Snr have vowed to express their disapproval by not attending, in a significant snub to the nominee.

Conventions are traditionally highly choreographed affairs but with figures like Mr Trump and Mr Sanders in the spotlight, strict choreography might go begging.